package com.sos.widget.view;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.widget.RadioGroup;

public class FlowRadioGroup extends RadioGroup {


    private static final String TAG = "MyRadioGroup";


    public FlowRadioGroup(Context context) {

        super(context);

    }


    public FlowRadioGroup(Context context, AttributeSet attrs) {

        super(context, attrs);

    }


    @Override

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        int widthSize = MeasureSpec.getSize(widthMeasureSpec);

        int widthMode = MeasureSpec.getMode(widthMeasureSpec);

        int heightSize = MeasureSpec.getSize(heightMeasureSpec);

        int heightMode = MeasureSpec.getMode(heightMeasureSpec);


        //调用ViewGroup的方法，测量子view

        measureChildren(widthMeasureSpec, heightMeasureSpec);


        //最大的宽

        int maxWidth = 0;

        //累计的高

        int totalHeight = 0;


        //当前这一行的累计行宽

        int lineWidth = 0;

        //当前这行的最大行高

        int maxLineHeight = 0;

        //用于记录换行前的行宽和行高

        int oldHeight;

        int oldWidth;


        int count = getChildCount();

        //假设 widthMode和heightMode都是AT_MOST

        for (int i = 0; i < count; i++) {

            View child = getChildAt(i);

            MarginLayoutParams params = (MarginLayoutParams) child.getLayoutParams();

            oldHeight = maxLineHeight;

            //当前最大宽度

            oldWidth = maxWidth;


            int deltaX = child.getMeasuredWidth() + params.leftMargin + params.rightMargin;

            if (lineWidth + deltaX + getPaddingLeft() + getPaddingRight() > widthSize) {//如果折行,height增加

                //和目前最大的宽度比较,得到最宽。不能加上当前的child的宽,所以用的是oldWidth

                maxWidth = Math.max(lineWidth, oldWidth);

                //重置宽度

                lineWidth = deltaX;

                //累加高度

                totalHeight += oldHeight;

                //重置行高,当前这个View，属于下一行，因此当前最大行高为这个child的高度加上margin

                maxLineHeight = child.getMeasuredHeight() + params.topMargin + params.bottomMargin;

                Log.v(TAG, "maxHeight:" + totalHeight + "---" + "maxWidth:" + maxWidth);


            } else {

                //不换行，累加宽度

                lineWidth += deltaX;

                //不换行，计算行最高

                int deltaY = child.getMeasuredHeight() + params.topMargin + params.bottomMargin;

                maxLineHeight = Math.max(maxLineHeight, deltaY);

            }

            if (i == count - 1) {

                //前面没有加上下一行的搞，如果是最后一行，还要再叠加上最后一行的最高的值

                totalHeight += maxLineHeight;

                //计算最后一行和前面的最宽的一行比较

                maxWidth = Math.max(lineWidth, oldWidth);

            }

        }


        //加上当前容器的padding值

        maxWidth += getPaddingLeft() + getPaddingRight();

        totalHeight += getPaddingTop() + getPaddingBottom();

        setMeasuredDimension(widthMode == MeasureSpec.EXACTLY ? widthSize : maxWidth,

                heightMode == MeasureSpec.EXACTLY ? heightSize : totalHeight);


    }


    @Override

    protected void onLayout(boolean changed, int l, int t, int r, int b) {

        int count = getChildCount();

        //pre为前面所有的child的相加后的位置

        int preLeft = getPaddingLeft();

        int preTop = getPaddingTop();

        //记录每一行的最高值

        int maxHeight = 0;

        for (int i = 0; i < count; i++) {

            View child = getChildAt(i);

            MarginLayoutParams params = (MarginLayoutParams) child.getLayoutParams();

            //r-l为当前容器的宽度。如果子view的累积宽度大于容器宽度，就换行。

            if (preLeft + params.leftMargin + child.getMeasuredWidth() + params.rightMargin + getPaddingRight() > (r - l)) {

                //重置

                preLeft = getPaddingLeft();

                //要选择child的height最大的作为设置

                preTop = preTop + maxHeight;

                maxHeight = getChildAt(i).getMeasuredHeight() + params.topMargin + params.bottomMargin;

            } else { //不换行,计算最大高度

                maxHeight = Math.max(maxHeight, child.getMeasuredHeight() + params.topMargin + params.bottomMargin);

            }

            //left坐标

            int left = preLeft + params.leftMargin;

            //top坐标

            int top = preTop + params.topMargin;

            int right = left + child.getMeasuredWidth();

            int bottom = top + child.getMeasuredHeight();

            //为子view布局

            child.layout(left, top, right, bottom);

            //计算布局结束后，preLeft的值

            preLeft += params.leftMargin + child.getMeasuredWidth() + params.rightMargin;


        }


    }

}